polyurethane, polystyrene, rock wool, glass wool insulation
Insulated panels today, with the recent research and developments for materials and advanced composite section design, are manufactured as light, but structurally sound building elements.The light, but structurally sound composite section panels were first used in military aircraft construction during the Second World War. Since then, there have been significant developments in design and manufacture of insulated composite section panels. Today, these panels are used at world-wide applications ranging from space shuttle construction to manufacturing of inside doors for our residential or office buildings.
Design of insulated panels requires state-of-the art solutions to meet specific requirements, such as thermal insulation, water and air-tight construction, structural safety, hygiene, fire safety, esthetic and envirnmental requirements. As insulated and coated inside and outside, these prefabricated panels are excellent water proofing and energy saving building materials Insulated panels offer practical and economical solutions to the word-wide construction needs and can be used in factories, industrial buildings and warehouses, food storage buildings and buildings in the agricultural sector, prefabricated structures, sports facilities including swimming pools, construction field offices, silos, supermarkets, shopping mall structures and military, government , municipal and residential buildings.
Metal Internal and External Sheet
Thicknesses of the inner and outer metal sheets of an insulated panel, are selected from the manufactures load tables, based on allowable spans between the panel structural supports. The metal sheets can be galvanized steel or aluminum.
Panel steel are hot dip galvanized by a continuous process in accordance with EN10142 Standards, with zinc coating weights varying between 100 gr/m2 and 275 gr/m2. Steel galvanizing is very effective against corrosion. For insulated panels, galvanized steel should be preprinted by coil coating. The thickness of galvanized sheets at load-bearing layers should be a minimum of 0.50mm.
Aluminum sheets can be flat or stucco embossed. Aluminum has a high corrosion resistance, high conductivity and a much higher elongation coefficient than galvanized steel. It is a preferred material to use in acidferous environments or heavy industrial areas. It can be used raw, lacquered or painted. The aluminum sheet thickness at load-bearing layers of insulated panels and trapezoidal sheets should not be less than 0,70mm.
Preprinted metal is galvanized steel or aluminum which is painted by coil coating in a continuous and automated process before fabrication. In this process, a coil of galvanized steel or aluminum is first unwound and generally, both sides of metal are cleaned. Oil and other contaminants are removed from the metal. Then the metal surface in chromed in preparation for painting. Before painting, a coat of primer is usually applied on both sides and the primed metal is then sent to an oven for curing. After oven curing, the metal is cooled and rewound. The top coat color is selected from the RAL Standard color catalogue.
With coil coating process, a uniform coating thickness can be maintained. As for the top coating, after an epoxy primer is applied, a polyester, polyvinylidene fluoride (PVDF), plastisol or polyurethane resin in used, considering the requirements for geographical location and environment conditions. Although, each of these coatings have different material properties, they all are used as liquid. In Turkey, the use of 5 micron primer and 20 micron polyester resin as a top coat, is generally accepted as sufficient. Painting assures much longer life span for metals and therefore, it is a cost-effective application. Coil coated metals can easily be bent or formed as required without any damage to coated surfaces.
In Europe, the life expectancy of coil coated metals, in areas with normal environmental conditions, ie., at inland locations away from the sea and locations with no air pollution concerns, is approximately 10 years. With a scheduled maintenance program, this duration can be increased to 40 years or even higher.
There are some benefits using coated steel with an epoxy primer. Epoxy primer provides a storage bond between galvanized steel and insulation core or insulation adhesive material if used, and therefore, a more structurally sound, insulated composite section panel is created. Since a primer is not applied to the insulation side face of stucco embossed aluminum sheets, a good adherence between insulation core and aluminum sheet cannot be obtained a separation occurs between the two layer.
Polyurethane is a rigid foam which is produced by joining polyol and isocyanate under special conditions with the presence of catalysts and other materials. It is a foam in which most of the foam cells remain closed. This gives the foam a high thermal insulation performance.
The maximum service temperature for rigid polyurethane is 70 ̊ C – 80 ̊ C. polyurethane stays thermally stable up to 100 ̊ C – 110 ̊ C. above these temperature, disintegration starts. It is a bacterial growth free material. Since polyurethane has a high compressive strength, it is used in wide-range applications.
PIR (Polyisocyanurate) is an improved type of polyurethane and used for composite section insulated panels. PIR foam is thermal stability much stonger and can meet the reqirements of Euroclass B.
Mineral Wool – Rock Wool / Glass Wool
Mineral Wool (Rock Wool or Glass Wool ) is a fibrous material. Therefore, it has very good thermal insulation and sound absorption coefficients. The most important physical difference between rockwool and glasswool is the difference between their heat resistance. The service temperature for rockwool is max. 750 ̊ C ,but, this value for glasswool goes down to 250 ̊ C. Rockwool can thermally stand up to 1000 ̊ C. Rockwool is a preferred insulation material to use in structures where combustible or flammable materials are stored. The fire resistibility of rockwool gets better when the insulation thickness is increased.
Mineral wool is cut and placed in panels in a fully automated production line, with fibers perpendicular to the panel surface in order to obtain a better compressive strength. Wool fiber cuts, which are sized to fit and fill the panel ribs, are placed in panels automatically with scattered joints.
Expandable Polystyrene (EPS) is produced from a mixture of polystyrene, which is a thermoplastic material manufactured from a petroleum product, and a gaseous, blowing agent pentane. With the help of pentane and through the use of steam, polystyrene is expanded to turn into a foam and takes the shape of the form used. Through this process, pentane replaces inside air. The voids filled with trapped air, gives EPS board a low thermal conductivity and therefore makes it a good thermal insulation material.
PVC and TPO roof Membrane is a flexible water proofing membrane which is reinforced with polyester and can be laminated with a geo textile felt backing. During construction, membrane sheets are welded together with hot air.
PVC and TPO Membrane stand up very well to direct sunlight and atmospheric conditions. Because of the polyester reinforcement, roof membrane has a height resistance to tear and impact. With geo textile felt backing, a strong adherence to roof panel insulation is obtained, but, also the direct contact between insulation and PVC and TPO membrane is eliminated.
Glass-reinforced plastic or GRP is a composite material made matrix reinforced by fine fibers made of glass. Although they are very light, they have very high mechanical strength and resistant against hard weather conditions such as wind and hails. Because of their low water absorption, they are resistant against water. There isn`t any deformation on temperature differences from -40 ̊ C to +120 ̊ C, because GRP sheets belong to Thermoset plastics group.
Upon request they can be used on different levels of fire resistance. According to B.S 476 Part 7 fire standard they are certificated as class 3 and class 1 (self-extinguishing). Because they are anti-corrosive, resistant against most chemicals and high temperature. They can be used in Acidic Environments, Food Foundations and chicken Farms.